How much you like a song depends mostly on how well you can predict what comes next. Great musicians play with your brain and expectations in the way that they get you to expect something, and then surprise you, before taking you back to comfortable terrain.

A great song surprises you, but not too much. It balances the familiar with the unknown and therefore creates the perfect mix of comfort and excitement.

While many areas of the brain light up simultaneously during music, such as your subcortical structures, auditory cortices, the hippocampus, and others, something unique happens the very first time you hear any song: a certain set of neurons fires together, and a unique, abstract, generalized imprint is created.

This can then be called upon any future time you hear this song or a part of it. That’s why when studies looked at the brain waves of people when they listened to songs and compared them to when they were just imagining the song in their head, the patterns were indistinguishable.

Neuroanatomically, music is being processed in parallel by many different regions.

• If we listen to Bach, our hair cells in the cochlea parse the incoming sound into its different frequency bands.
• Then, electrical signals are sent to the primary auditory cortex to inform it about which frequencies are present in the signal.
• Simultaneously, regions in the temporal lobe, including the superior temporal sulcus and the superior temporal gyrus, assist in distinguishing the different timbres.
• We can then label some of those timbres by retrieving the memories of similar sounds that we’ve heard before, using the hippocampus.

There are 2competing theories.

• The constructivist theory argues that the brain stores relational information about objects and ideas, rather than explicit information about them. Thus, upon retrieval, we have to construct a memory representation out of these relations (e.g. pitch relations of a melody).
• The competing theory is known as the record-keeping theory - most of our experiences are preserved accurately and with near-perfect fidelity.

Ample evidence exists for both, which eventually led researchers to develop a new theory that is capable of incorporating both of its predecessors.

Our brains have mirror neurons, which are neurons that fire both when performing an action and when observing someone else performing that action.

Scientists have tested this as a theory and proved that, for example, when people listened to or watched someone eat an apple, their own neurons in the mouth movement area were activated. This is the brain’s way to train and prepare the organism to make movements that it has not made before.